Engine



Aug. 15, 1939. s. B. ROBBINS E AL 2,169,289

ENGINE Filed May 24, 19:57 a sheets-sheet 1 aef 0 115M022 JcZoZZ 7INVENTORS myam ed.

ATTORNEYS Aug. 15, 1939.

s. B. ROBBINS :r m.

ENGINE Filed May 24, 1937 5 Sheets-Sheet 2 62177241?) 1 .055 Mrsfia272$, 22 1NVENTOR5 Aug. 15, 1939. s. B. ROBBINS El AL ENGINE Filed May24, 1937 3 Sheets-Sheet 3 mv lm m mm BJWN nth z@ Samuel 5. Robbins ATTORN EYS Patented Aug. 15, 1939 UNITED STATES ENGINE Samuel B. Robbins,Boise City, Okla., and Mar- Ellensburg, Wash; said Robbins assignor ofone-half to said Scholl Application May 24, 1937, Serial No. 144,514

shal P. Scholl,

2 Claims.

This invention relates to an engine of the reciprocating type and moreparticularly to means for connecting the crank shaft to the connectingrods of the pistons for eliminating piston drag on the walls of thecylinder and thereby materially retard cylinder wall and piston wear.

With these and other objects in view this invention consists in certainnovel features of construction, combination and arrangement of parts tobe hereinafter more fully described and claimed.

For a complete understanding of our invention, reference is to be had tothe following description and accompanying drawings, in which Figure 1is a transverse sectional view illustrating an engine constructed inaccordance with our invention.

Figure 2 is a similar view illustrating another position of theconnecting means than the positions shown in Figure 1.

Figure 3 is a sectional 33 of Figure 1.

Figure 4 is a sectional view taken on the line 4-4 of Figure 2.

Figure 5 is a diagrammatical view showing the present invention bringingabout a travel of the connecting rod in a substantially straight pathand the various positions of the pistons in accordance with the variouspositions of the cams.

Figures 6 to 13 inclusive illustrate the various positions of the camfor operating the pitman whereby the travel of the connecting rod ismaintained in a substantial straight path.

Referring in detail to the drawings, the numeral I indicates thecylinders of an engine having reciprocating pistons 2 and mounted upon abase 3, the latter extending laterally of said cylinders and providedwith a removable crank case 4. The pistons 2 are equipped with the usualconnecting rods 5, which extend into the base. Journaled to the base andlocated laterally of the pistons is a crank shaft 6. An auxiliary shaft1 is journaled inv the base with the crank shaft 6 located between saidauxiliary shaft 1 and the connecting rods 5. Arms 8 are integral withthe shaft 1 and have pivoted thereto floating levers 9, the oppositeends of which are joumaled on the connecting rods 5 as shown at 5'.Auxiliary connecting rods H] are pivoted to the levers 9 as shown at 9'and are journaled tothe cranks of the crank shaft 6. An arm I l isformed integrally with the auxiliary shaft 7 and extends in an oppositedirection to the arms 8 and has pivoted thereto a pitman I2 slidablysupported by a bracket l3 carried by the crank case 4. The

view taken on the line PATENT OFFIQE free end of the pitman terminatesin a head M which rides on oppositely arranged cams l5. The cams form anintegral part of the crank shaft.

A coil spring 48 is interposed between the bracket I 3 and the head M tomaintain the latter in con- 5 tact with the cams.

In conventional engine construction where the connecting rods of thepistons are journaled directly to the cranks of the crank shaft causesthe pistons to drag against opposite walls of the 10 cylinders duringthe reciprocation of said pistons thereby wearing away said walls andcause said cylinders to rapidly assume a substantially egg shape causingpiston slaps, loss of compression and the passing of fuel by the pistonsto the crank case and consequently render an ineflicient operatingengine. An engine constructed in accordance with our invention andheretofore specifically described will permit the connecting rods 5 totravel in a substantially vertical path throughout their entire movementand thereby eliminate the pistons from dragging against opposite wallsof the cylinders.

To clearly describe the substantially straight line travel of aconnecting rod during the down and up strokes of a piston, reference ismade to Figure 5 which is a diagrammatical view showing the path oftravel the connecting rod is made to take by the present invention. Thisshowing is based on one complete revolution of the crank shaft, whereineight positions of the crank are given, each position being forty fivedegrees apart, also showing the eight positions of the piston, the eightpositions of the pivot 9, eight positions of the cams l5 and eightpositions of the journal 5'. This view further indicates by thecharacter A the positions taken by the arms 8 and H during the eightpositions of the crank of the crank shaft. Thus during one revolution ofthe crank of the crank shaft the piston moves down from its uppermostposition to its lowermost position and back to its uppermost position.During this travel of the piston the journal 5' travels in asubstantially straight line. Consequently the connecting rod moves in a.path according to: the path of travel of the journal 5' and the lever 9moves back and forth for a limited distance by the oscillatory movementsof the arms 8 and l! actuated by the cams acting on the head I4 of thepitman l2.

Having described the invention, we claim:

1. An engine comprising cylinders, a base for said cylinders andextending laterally of the latter, pistons reciprocally mounted in thecylinders, connecting rods carried by said pistons and ex- 55 tendinginto the base, a crank shaft journaled in the base laterally of thecylinders, an auxiliary shaft journaled to the base laterally of thecrank shaft and the cylinders, arms integral with the auxiliary shaft,floating levers pivoted to said arms and the connecting rods, auxiliaryconnecting rods connecting the floating levers and the cranks of thecrank shaft, an arm formed on the auxiliary shaft and extending in anopposite direction from the direction of the first-named arms, a pltmanslidably supported by the base and having one end pivoted to thesecond-named arm, and cams carried by the crank shaft for operating thepitman.

2. An engine comprising cylinders, a base for said cylinders andextending laterally of the latter, pistons reciprocally mounted in thecylinders, connecting rods carried by said pistons and extending intothe base, a crank shaft journaled in the base laterally of thecylinders, an auxiliary shaft journaled to the base laterally of thecrank shaft and the cylinders, arms integral with the auxiliary shaft,floating levers pivoted to said arms and the connecting rods, auxiliaryconnecting rods connecting the floating levers and the cranks of thecrank shaft, an arm formed on the auxiliary shaft and extending in anopposite direction from the direction of the first-named arms, a pitmanslidably supported by the base and having one end pivoted to thesecond-named arm, a head on the free end of the pitman, oppositelyarranged cams formed on the crank shaft and engaging said head, andspring means engaging the head to cause the latter to ride the cams.

MARSHAL P. SCI-IOLL. SAMUEL B. ROBBINS.

